This invention relates generally to the field of mixing, and in particular to the mixing of fluids. In one particular aspect, the invention relates to the mixing of biological fluids within a chamber which is disposed within a heated environment.
Methods for using arrays of polymers to identify receptors with specific affinities for one of the polymers in the array are known. For example, one method uses immobilized antibodies to analyze binding to peptide ligands or vice-versa. Another type of method uses immobilized oligonucleotides to analyze hybridization to a target nucleic acid. For instance, U.S. patent application Ser. No. 08/624,312, filed Mar. 26, 1996, the complete disclosure of which is herein incorporated by reference, describes apparatus and methods for carrying out repeated hybridizations of a target nucleic acid to an array of nucleic acid probes. Such polymer arrays are described in, e.g., U.S. Pat. No. 5,143,854 and published PCT Application Nos. WO90/15070 and WO92/10092, the complete disclosures of which are herein incorporated by reference. These polymer arrays are nucleic acid arrays which include a plurality of different polynucleotides coupled to a substrate in different known locations.
In one exemplary arrangement, such arrays are packaged within a housing, like those described in, e.g., pending U.S. patent application Ser. No. 08/624,312, previously incorporated by reference, Ser. Nos. 08/485,452, filed Jun. 7, 1995, and 08/528,173, filed Sep. 19, 1995, and published PCT Application No. WO95/33846. The disclosures of all of these references are herein incorporated by reference. In brief, such a housing typically includes a body having a reaction cavity or hybridization chamber. The array or substrate is mounted over the cavity on the body such that the front side of the array substrate, e.g., the side upon which the polynucleotides are situated, is in fluid communication with the cavity. The cartridge includes inlet and outlet ports to allow various fluids to be introduced into and removed from the hybridization chamber.
During hybridization, it is often desirable to provide an efficient and effective way to mix the fluids within the chamber. This can be challenging since the chamber is typically in a temperature controlled environment, such as in an oven. Additionally, in at least one embodiment, the interior of the chamber is narrow, and it can be difficult to mix or agitate the fluid when within the chamber.
Hence, it would be desirable to provide devices, systems and methods to facilitate the mixing of fluids which are held within a hybridization chamber to improve the hybridization process. Such devices, systems and methods should be cost effective, easy to use, and be compatible with the constraints of the hybridization process. In particular, it would be desirable if mixing of the fluid could be facilitated while the chamber is within a temperature controlled environment, such as an oven.
The invention provides systems, devices and methods for facilitating the mixing of various fluids within a chamber. In one exemplary embodiment, a system is provided which comprises at least one cartridge having a chamber for holding a fluid (which is preferably a biological fluid), with the chamber including a generally planar face. The system further includes a rotatable body having a rotational axis. The rotatable body includes at least one mounting element to removably mount the cartridge to the rotatable body such that the face of the chamber is generally perpendicular to the rotational axis.
In one exemplary aspect, the mounting element comprises a pair of opposing walls which each include at least one slot. The slots are arranged such that the cartridge is insertable into the slots. Conveniently, the rotatable body may also include a base which connects the pair of walls. Preferably, the rotational axis extends through one of the walls. In this way, the cartridge will be spaced apart from the rotational axis to facilitate mixing of the fluid when the body is rotated.
In another aspect, the opposing walls are parallel to each other and the slots are configured such that the face of the chamber is generally perpendicular to the walls when placed into the slots. Preferably, at least one of the slots is keyed such that the cartridge is insertable into the slot in only one orientation. Optionally, each wall may include a plurality of slots which are arranged such that multiple cartridges may be inserted into the slots in a parallel arrangement. It will be appreciated that the rotatable body may include additional numbers of parallel walls which each include slots so that multiple cartridges may be removably mounted to the body.
In one aspect, a lid is also provided and is operably attached to at least one of the walls. The lid is movable between an open and a closed position, with the lid securing the cartridge within the slots when the lid is in the closed position. At least one coupling element is preferably operably attached to the body in alignment with the rotational axis. In this way, the coupling element may couple the rotatable body to a rotation mechanism.
In one particular aspect, the chamber includes a pair of planar spaced apart faces which define an interior having the fluid. The faces are generally rectangular or square in geometry, and the cartridge is mounted to the body such that the faces are generally perpendicular to the rotational axis to facilitate mixing of the fluid within the chamber.
The body will preferably be rotated about the rotational axis at a rate in the range from about 30 rpm to about 90 rpm, and more preferably from about 50 rpm to about 60 rpm. Further, the rotational body will preferably be placed within a temperature controlled environment during rotation of the body. In one particular aspect, the chamber is heated to a temperature in the range from about 30xc2x0 C. to about 60xc2x0 C., and more preferably from about 40xc2x0 C. to about 50xc2x0 C., while the body is rotating. Such heating may be accomplished, for example, by placing the rotatable body within an oven.
In a preferred aspect, the device will be fabricated of transparent plastic materials, such as PLEXIGLAS or other suitable lightweight, rigid, machinable material and be a generally amber color such that wavelengths of light in the range of 200 nm to 700 nm will be filtered out.